The present invention relates to a transmission which is either strictly or approximately homokinetic, both cases being referred to as "substantially homokinetic" in the present description.
In most applications substantially homokinetic transmissions are provided between two shafts which are not coaxial but both of which have predetermined fixed positions in space.
This is so particularly in the case of two shafts which are parallel but offset relative to one another, or in the case of two converging shafts. In both cases the homokinetic condition may be fulfilled without particular difficulty by means of a pair of universal joints.
On the other hand, when one of the shafts, for example the driven shaft, has an inclination which is not fixed but which is variable in relation to the other shaft, for example the driving shaft, it has not hitherto been found possible to obtain between the two shafts, under good conditions, transmission which remains substantially homokinetic, particularly with a large variation in the angle of inclination.
There are various applications in which two shafts, of which one drives the other, have a variable inclination in relation to one another and where it is desirable to obtain substantially homokinetic conditions in the drive, whatever the inclination within predetermined limits. This is the case, for example, in a dredger which comprises a floating hull and a boom whose inclination in relation to the floating hull is variable and where it is desired to drive a submerged rotatable pump disposed at the end of the boom with the aid of a motor disposed on the hull.
It is important that the rotation of a shaft of any kind should be as regular as possible in order to avoid torsional vibration phenomena, wear, and possibly impairment of the operation of the driven components.
The present invention relates to a substantially homokinetic transmission between two shafts, of which one has a fixed position and the other a variable inclination in relation to the first, which transmission is of simple construction, strong, and efficient.